Unit for combustion of process exhaust gas and production of hot air

Abstract

Unit for thermal incineration of non-explosive gases with minor amounts of organic pollutants and for production of hot air, and which can be adapted to various types of supplementary fuel. There is a combustion chamber which consists of a flame pipe inside an outer jacket. Through the space therebetween, incoming process gas is led as coolant. At its front end, the combustion chamber has a burner for supplementary fuel and a mixing-in zone for process gas. The process gas rapidly mixes with the hot combustion gases in the flame, the gas reaching its reaction temperature directly. Powerful turbulence in the mixing-in zone gas, film-layer cooling, convective cooling and even flow give highly efficient and pure combustion while keeping the flame pipe temperature low enough to prevent corrosion.

We claim: 
     
       1. Unit for combustion of nonexplosive process gases containing small amounts of organic compounds and for production of hot air directly usable for drying and heating, or for the like uses, the unit comprising a combustion chamber comprised of metal, a burner for burning supplementary fuel, the burner being located at one end of the combustion chamber and outside of the combustion chamber, and the burner being adaptable for burning different types of supplementary fuel; the combustion chamber comprising a flame pipe having a front portion at the burner and including an inlet cone for the flame from the burner, the inlet cone being located at the one end of the combustion chamber at the front portion and widening away from the one end; an outer jacket extending around, at a distance from and concentric to the flame pipe for conducting the process gas into the space defined between the flame pipe and the outer jacket, whereby the process gas moving through the space may provide convective cooling of the wall of the flame pipe, the flame pipe having an outlet remote from the inlet cone, an intake for the process gas to the space, the intake being located near the outlet of the flame pipe, an annular chamber located around the outside of the inlet cone and inside the outer jacket for redirecting the process gas in a direction back toward the intake to the space, and an extension of the annular chamber between the front end of the flame pipe and the inlet cone into which the process gas is redirected for cooling the outside of the inlet cone, an inlet slot for process gas from the annular chamber into the inlet cone, the inlet slot being located at the front portion of the flame pipe and being for directing process gas for blowing over and for film-cooling of the inside of the inlet cone, outlet holes for the process gas from the annular chamber extension and located at the wider rear end of the inlet cone for mixing process gas into the flame in the inlet cone and combustion of the pollutant. 
     
     
       2. Unit according to claim 1, further comprising annular slot means in the inlet cone spaced between the inlet slot and the outlet holes for conducting process gas from the extension of the annular chamber into the inlet cone, the annular slot means being for directing process gas for blowing over for film-cooling the portion of the inlet cone to the rear of the annular slot and in front of the outlet holes. 
     
     
       3. Unit according to claim 1 or 2, further comprising vanes arranged at the place of redirection of the process gas located between the annular chamber and the extension thereof for imparting to the process gas a rotary movement which evens out layering. 
     
     
       4. Unit according to claim 1, further comprising an annular chamber defined around the intake to the space for the process gas for even distribution of the process gas. 
     
     
       5. Unit according to claim 1, further comprising a temperature sensor at the outlet of the flame pipe for measuring the temperature which is related to the amount of supplementary fuel and process gas being burned.